package com.tian.dataStructure.stack;

import java.util.Scanner;

public class ArrayStackDemo {
    public static void main(String[] args) {
        ArrayStack arrayStack = new ArrayStack(4);
        String key="";
        boolean loop=true;
        Scanner scanner=new Scanner(System.in);

        while (loop){
            System.out.println("show: 表示显示栈");
            System.out.println("exit: 退出程序");
            System.out.println("push: 表示添加数据到栈（入栈）");
            System.out.println("pop: 表示从栈取出数据（出栈）");
            System.out.println("请输入你的选择");
            key=scanner.next();

            switch (key){
                case "show":
                    arrayStack.list();
                    break;
                case "push":
                    System.out.println("请输入一个数");
                    int value = scanner.nextInt();
                    arrayStack.push(value);
                    break;
                case "pop":
                    try {
                        int res = arrayStack.pop();
                        System.out.printf("出栈的数据是 %d\n",res);
                    }catch (Exception e){
                        System.out.println(e.getMessage());
                    }
                    break;
                case "exit":
                    scanner.close();
                    loop=false;
                    break;
                default:
                    break;
            }
        }
        System.out.println("程序退出~~~~~~");
    }
}

class ArrayStack{
    private int[] stack;
    private int maxSize;
    private int top=-1;

    public ArrayStack(int maxSize) {
        this.maxSize = maxSize;
        stack=new int[maxSize];
    }

    public boolean isFull(){
       return top==maxSize-1;
    }

    public boolean isEmpty(){
        return top==-1;
    }

    public void push(int num){
        if (isFull()){
            System.out.println("栈满");
            return;
        }
        top++;
        stack[top]=num;
    }

    public int pop(){
        if (isEmpty()){
            throw new RuntimeException("栈空");
        }
        int value = stack[top];
        top--;
        return value;
    }

    public void list(){
        if (isEmpty()){
            System.out.println("栈空");
            return;
        }
        for (int i=top;i>=0;i--){
            System.out.printf("stack[%d]=%d\n",i,stack[i]);
        }
    }
}
